We propose to explore the utility of bacteriophages in reducing Salmonella contamination in poultry. Salmonellosis remains a substantive public health concern in the United States; poultry serve as the primary reservoir for human salmonellosis. Phage therapy is an attractive modality for reduction of Salmonella contamination because: l) bacteriophage are absolutely specific for prokaryotes; 2) the high selectively of bacteriophage permits targeting of specific pathogens, leaving desirable flora intact; 3) extensive recent use in the former Soviet Union and commercial sales in the 1940's in the United States (Eli Lilly & Co.) underscore the safety of phage therapy; 4) phage treatment is likely to render processed poultry free of specific Salmonella species, and 5) phage production through fermentation and purification is likely to be cost-effective for large-scale application in the poultry industry. In our studies to date, we have identified and initially characterized seven Salmonella monophages which provide broad-spectrum coverage for the most common Salmonella serotypes. We also have demonstrated the efficacy of these phages in eliminating target bacteria from environmental surfaces. As a necessary step in moving toward subsequent field trials, we are proposing to (1) Evaluate the utility of phage application at various points of chicken processing cycle, and (2) Optimize conditions for large scale phage production. Our ultimate objective is to develop a commercially viable system of phage products and delivery, which can be incorporated into an overall program of Salmonella control. PROPOSED COMMERCIAL APPLICATIONS: A multivalent bacteriophage product will be developed, to serve as a component of a producer's overall program to limit Salmonella contamination of product. Commercial applications will include: (1) the phage product itself and (2) an associated service system to assist producers in monitoring flocks, modifying the phage product in response to development of resistance, and producing "custom" phage products for specific problematic Salmonella strains.